21021022204 has 24 divisors (see below), whose sum is σ = 45276048608. Its totient is φ = 8316008640.

The previous prime is 21021022171. The next prime is 21021022207. The reversal of 21021022204 is 40222012012.

It is a super-2 number, since 2×21021022204² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021022207) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28874667 + ... + 28875394.

Almost surely, 2^21021022204 is an apocalyptic number.

It is an amenable number.

21021022204 is an abundant number, since it is smaller than the sum of its proper divisors (24255026404).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21021022204 is a wasteful number, since it uses less digits than its factorization.

21021022204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57750085 (or 57750083 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 21021022204 its reverse (40222012012), we get a palindrome (61243034216).

The spelling of 21021022204 in words is "twenty-one billion, twenty-one million, twenty-two thousand, two hundred four".